/*
 * Created on 26-Jan-2006
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package com.aelitis.azureus.core.networkmanager.impl;

import java.io.IOException;
import java.nio.ByteBuffer;

public class TransportHelperFilterInserter implements TransportHelperFilter {
    private TransportHelperFilter target_filter;

    private ByteBuffer read_insert;

    public TransportHelperFilterInserter(TransportHelperFilter _target_filter, ByteBuffer _read_insert) {
        target_filter = _target_filter;

        read_insert = _read_insert;
    }

    public long write(ByteBuffer[] buffers, int array_offset, int length)

    throws IOException {
        return (target_filter.write(buffers, array_offset, length));
    }

    public long read(ByteBuffer[] buffers, int array_offset, int length)

    throws IOException {
        long total_read = 0;

        if (read_insert != null) {

            int pos_before = read_insert.position();

            for (int i = array_offset; i < array_offset + length; i++) {

                ByteBuffer buffer = buffers[i];

                int space = buffer.remaining();

                if (space > 0) {

                    if (space < read_insert.remaining()) {

                        int old_limit = read_insert.limit();

                        read_insert.limit(read_insert.position() + space);

                        buffer.put(read_insert);

                        read_insert.limit(old_limit);

                    } else {

                        buffer.put(read_insert);
                    }

                    if (!read_insert.hasRemaining()) {

                        break;
                    }
                }
            }

            total_read = read_insert.position() - pos_before;

            if (read_insert.hasRemaining()) {

                return (total_read);

            } else {

                read_insert = null;
            }
        }

        total_read += target_filter.read(buffers, array_offset, length);

        return (total_read);
    }

    public boolean hasBufferedWrite() {
        return (target_filter.hasBufferedWrite());
    }

    public boolean hasBufferedRead() {
        return (read_insert != null || target_filter.hasBufferedRead());
    }

    public TransportHelper getHelper() {
        return (target_filter.getHelper());
    }

    public void setTrace(boolean on) {
        target_filter.setTrace(on);
    }

    public boolean isEncrypted() {
        return (target_filter.isEncrypted());
    }

    public String getName(boolean verbose) {
        return (target_filter.getName(verbose));
    }
}
